from rest_framework import serializers

from goods.models import SKU


class CartSerializer(serializers.Serializer):

    """
    购物车数据序列化器
    """

    sku_id = serializers.IntegerField(label='sku id ', min_value=1)
    count = serializers.IntegerField(label='数量', min_value=1)
    selected = serializers.BooleanField(label='是否勾选', default=True)

    def validate(self, attrs):

        # 判断商品是否存在
        try:
            sku = SKU.objects.get(id=attrs['sku_id'])
        except:
            raise serializers.ValidationError('商品不存在')

        # 库存判断
        if attrs['count'] > sku.stock:
            raise serializers.ValidationError('库存不足')

        return attrs


class CartSKUSerializer(serializers.ModelSerializer):
    """
    购物车商品数据序列化器
    """
    count = serializers.IntegerField(label='数量', read_only=True)
    selected = serializers.BooleanField(label='是否勾选', read_only=True)

    class Meta:
        model = SKU
        fields = '__all__'


class CartDeleteSerializer(serializers.Serializer):
    """
    删除购物车数据序列化器
    """
    sku_id = serializers.IntegerField(label='商品ｉｄ', min_value=1)

    def validate_sku_id(self, attrs):
        try:
            sku = SKU.objects.get(id=attrs)
        except SKU.DoesNotExist:
            raise serializers.ValidationError('商品不存在')

        return attrs


class CartSelectAllSerializer(serializers.Serializer):
    """
    购物车全选
    """
    selected = serializers.BooleanField(label="全选")